/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.apache.mina.core.future;

import org.apache.mina.core.session.IoSession;

/**
 * An {@link IoFuture} for asynchronous connect requests.
 *
 * <h3>Example</h3>
 * <pre>
 * IoConnector connector = ...;
 * ConnectFuture future = connector.connect(...);
 * future.awaitUninterruptibly(); // Wait until the connection attempt is finished.
 * IoSession session = future.getSession();
 * session.write(...);
 * </pre>
 */
public interface ConnectFuture extends IoFuture {
	/**
	 * Returns {@link IoSession} which is the result of connect operation.
	 *
	 * @return The {@link IoSession} instance that has been associated with the connection,
	 * 		if the connection was successful, {@code null} otherwise
	 */
	@Override
	IoSession getSession();

	/**
	 * Returns the cause of the connection failure.
	 *
	 * @return <tt>null</tt> if the connect operation is not finished yet,
	 * 		or if the connection attempt is successful, otherwise returns the cause of the exception
	 */
	Throwable getException();

	/** @return {@code true} if the connect operation is finished successfully. */
	boolean isConnected();

	/** @return {@code true} if the connect operation has been canceled by {@link #cancel()} method. */
	boolean isCanceled();

	/**
	 * Sets the newly connected session and notifies all threads waiting for this future.
	 * This method is invoked by MINA internally. Please do not call this method directly.
	 *
	 * @param session The created session to store in the ConnectFuture insteance
	 */
	boolean setValue(Object session);

	/**
	 * Sets the exception caught due to connection failure and notifies all threads waiting for this future.
	 * This method is invoked by MINA internally. Please do not call this method directly.
	 *
	 * @param exception The exception to store in the ConnectFuture instance
	 */
	void setException(Throwable exception);

	/**
	 * Cancels the connection attempt and notifies all threads waiting for this future.
	 *
	 * @return {@code true} if the future has been cancelled by this call,
	 *        {@code false} if the future was already cancelled.
	 */
	boolean cancel();

	@Override
	ConnectFuture await() throws InterruptedException;

	@Override
	ConnectFuture awaitUninterruptibly();

	@Override
	ConnectFuture addListener(IoFutureListener<?> listener);

	@Override
	ConnectFuture removeListener(IoFutureListener<?> listener);
}
